Eleutheroside B or E, the main component of Acanthopanax, can relieve
fatigue, enhance memory, and improve human cognition. Numerous studies have confirmed that high doses of
acetylcholine significantly attenuate clinical symptoms and delay the progression of
Alzheimer's disease. The present study replicated a rat model of aging induced by injecting
quinolinic acid into the hippocampal CA1 region. These rats were intraperitoneally injected with low, medium and high doses of
eleutheroside B or E (50, 100, 200 mg/kg), and rats injected with
Huperzine A or PBS were used as controls. At 4 weeks after administration, behavioral tests showed that the escape latencies and errors in searching for the platform in a Morris water maze were dose-dependently reduced in rats treated with medium and high-dose
eleutheroside B or E.
Hematoxylin-
eosin staining showed that the number of surviving hippocampal neurons was greater and pathological injury was milder in three
eleutheroside B or E groups compared with model group. Hippocampal homogenates showed enhanced
cholinesterase activity, and dose-dependent increases in
acetylcholine content and decreases in
choline content following
eleutheroside B or E treatment, similar to those seen in the
Huperzine A group. These findings indicate that
eleutheroside B or E improves learning and memory in aged rats. These effects of
eleutheroside B or E may be mediated by activation of
cholinesterase or enhanced reuse of
choline to accelerate the synthesis of
acetylcholine in hippocampal neurons.